2002/09/27 by G. Bjornsson, J. Hjorth, K. Pedersen +1 · 1 citation
Physics and Astronomy · #astro-ph
paper · pdf · doi:10.1086/345292
published as Astrophys.J. 579 (2002) L59-L62 · 5 pages, 1 figure. To appear in ApJL
arxiv created 2002/09/27 · arxiv updated 2009/12/01
The optical lightcurve of GRB010222 exhibited one of the slowest decays of any gamma-ray burst to date. Its broadband properties have been difficult to explain with conventional afterglow models, as they either require the power law index of the underlying electron energy distribution to be low, p<2, or that the outflow is quasi-spherical thus reviving the energy problem. We argue that the slow decay of GRB 010222 and a linear polarization of 1.36± 0.64%, is naturally explained by a jet model with continuous energy injection. The electron energy distribution then has p=2.49±0.05, fully consistent with the expectation from detailed modelling of acceleration in relativistic shocks, that p>2, thus alleviating the ``p-problem''.